Closure

ABSTRACT

A safety closure for a container comprises inner and outer caps with ratchet teeth formed on the skirts of the caps for abutting and turning the inner cap on the container when a torque is applied to the outer cap in the application direction. When the outer cap is turned in the removal direction, the ratchet teeth slide by each other without turning the inner cap. With exertion of a downward axial force on the outer cap, a segmented ring forming a flexible dome on a central portion of one of the caps is flexed by a facing rigid central portion on the other cap thereby allowing radially extending teeth on the inner surface of the top end wall of the outer cap to move axially toward and into engagement with radially extending teeth on the upper surface of the top end wall of the inner cap. Thus, removal of the closure can be accomplished only with a downward axial force interengaging the radially extending teeth on the inner and outer caps and with a simultaneous applied torque in the removal direction.

United States Patent [1 1 Cistone 1 Dec. 4, 1973 CLOSURE [75] Inventor: David R. Cistone, Lancaster, Pa.

[73] Assignee: Kerr Glass Manufacturing Corporation, Los Angeles, Calif.

22 Filed: Feb. 4, 1972 21 Appl. No.: 223,450

[52] U.S. Cl. 215/9 [51] Int. Cl. 865d 55/02, A61 j 1/00 [58] Field of Search 215/9, 46 R [56] References Cited UNITED STATES PATENTS 3,682,343 8/1972 Landen 215/9 3,055,524 9/1962 Glasbrenner 215/9 3,485,403 12/1969 Hedgewick et al. 215/9 Primary ExaminerGeorge T. Hall Attorney-William E; Anderson et al.

[57] ABSTRACT A safety closure for a container comprises inner and outer caps with ratchet teeth formed on the skirts of the caps for abutting and turning the inner cap on the container when a torque is applied to the outer cap in the application direction. When the outer cap is turned in the removal direction, the ratchet teeth slide by each other without turning the inner cap. With exertion of a downward axial force on the outer cap, a segmented ring forming a flexible dome on a central portion of one of the caps is flexed by a facing rigid central portion on the other cap thereby allowing radially extending teeth on the inner surface of the top end wall of the outer cap to move axially toward and into engagement with radially extending teeth on the upper surface of the top end wall of the inner cap. Thus, removal of the closure can be accomplished only with a downward axial force interengaging the radially extending teeth on the inner and outer caps and with a simultaneous applied torque in the removal direction.

5 Claims, 5 Drawing Figures CLOSURE This invention relates to a safety closure for a container which can be applied and removed readily by one having knowledge of how to manipulate the closure but is relatively safe from removal from the container by children. The closure comprises inner and outer caps with ratchet teeth formed on the skirts of the caps for abutting and turning the inner cap on the container when a torque is applied to the outer cap in the application direction. When the outer cap is turned in the removal direction, the ratchet teeth slide by each other without turning the inner cap. With exertion of sufiicient downward force on the closure, radially extending teeth on the outer cap are brought into interlocking engagement with radially extending teeth on the inner cap and a torque applied in the removal direction will turn the inner cap for release from the container.

One safety closure of this general kind is disclosed in U.S. Pat. No. 3,055,524 to Glasbrenner in which the inner and outer caps are formed with facing circular top end walls. The top end wall of the outer cap is formed with a downwardly projecting dome abutted against a similar upwardly projecting dome on the top end wall of the inner cap. As the domes project for a distance from their respective end walls greater than the distance which teeth project, the abutted domes space the teeth on the respective caps from interlocking engagement until the top end wall of the cap is deflected downwardly sufiiciently to interlock its teeth with those on the underlying inner cap. More specifically, the annular portion of the upper cap end wall between its dome and encircling skirt is deflected upon exertion of sufficient downward force on the top of the outer cap.

Safety closures of the foregoing kind have been com mercially very successful; but for some uses, those who remove the closures from the containers express a desire that the amount of axial force or pressure required for removal be reduced. For example, housewives prefer to exert only a slight downward force and turning torque to open caps on containers. Because these safety closures of the foregoing kind have been made in large quantities and have met with wide commercial success, it is most desirable that only minimal changes be made which do not result in large scale retooling'or new modes of manipulation for removal and replacement but which'reduce significantly the amount of axial force required for removal of the closure from the container.

Accordingly, an object of the present invention is to provide a safety closure of the foregoing kind which requires less downward force, is contrasted to prior art safety closures of this kind, for engaging the interlocking teeth and for facilitating removal .of the closure from the container.

Other objects and advantages of the invention will become apparent from the following detailed description:

FIG. 1 is an enlarged, perspective view of a safety closure embodying the novel features of the invention;

FIG. 2 is an exploded perspective view of inner and outer caps of the dispenser closure of FIG. 1 with a portion of the skirt of the outer cap broken away;

FIG. 3 is a bottom view of the outer cap without the inner cap being present;

FIG. 4 is a cross-sectional view taken substantially along the line 44 of FIG. 1; and

FIG. 5 is a fragmentary plan view of the top of the inner cap.

As shown in the drawings for the purposes of illustration, the invention. is embodied, very generally, in a safety closure 11 which comprises an outer cap 12 overlying an inner cap 14 with the inner and outer caps being coaxially aligned. To fasten the closure to a container (not shown), a generally cylindrical skirt 15 of the inner cap is formed with a container fasteneing means 17 such as a spiral screw thread 18. To apply the closure by screwing the thread 18 onto a threaded neck of a container, a series of ratchet teeth 19 on the skirt 15 of the inner cap project radially outwardly for interlocking engagement with ratchet teeth 20 on an inner side of a depending generally cylindrical skirt 21 for the outer cap 12. More specifically, when the outer cap is turned in the application direction (which is counterclockwise, in this instance) tooth abutment walls 23 on the ratchet teeth 20 of the outer cap 12 abut and interlock with similar tooth abutment walls 25 on the ratchet teeth 19 of the inner cap and continued turning of the outer cap screws the inner cap onto the container. On the other hand, when the outer cap 12 is rotated in the removal direction (which is clockwise as viewed in FIG. 2) inclined susfaces 27 of the outer cap ratchet teeth 20 slide over inclined surfaces 29 of the inner cap ratchet teeth 19 without an unscrewing of the inner cap. That is, the torque exerted on the inner cap teeth by the sliding outer teeth is not sufficient to overcome the frictional resistance between the thread 18 and the container thread. Thus, a child or other person who merely turns the outer cap on the inner cap will not unscrew the inner cap and gain access to the contents of the container.

To remove the closure from the container, it is necessary to press downward on the outer cap 12 and simultaneously to apply a torque to'the outer cap skirt 21 in the removal direction. With the downward pressure of sufficient magnitude, radially extending teeth 31, as best seen in FIGS. 2 and 4, on an inner side of the top end wall 33 of the outer cap are moved downwardly into interlocking engagement with similar radially extending teeth 35 (FIG. 5) on top end wall 37 for the inner cap 14. With the respective radially extending teeth 31 and 35 interlocked, a torque applied to the outer cap skirt 21 in the removal direction causes a similar torque to be exerted through the interengaged teeth to the inner cap which then unscrews its thread 18 from the container. 7

In the prior art kind of closures such as disclosed in the Glasbrenner US. Pat. No. 3,055,524, the outer cap 12 and the inner cap 14 each had a dome similar to dome 39 shown on the inner cap 14, as shown in FIG. 4. More specifically, a downwardly projecting dome (identified by the numeral 9 in the patent) composed of a solid body of material was formed on the inner side of the outer cap top end wall with its lower rounded surface abutting the upper rounded surface of the dome on the inner cap and thereby holding the teeth of the outer cap above and spaced from the teeth of the inner cap. This solid upper dome rigidified the central portion of top end wall with the result that an annular and teeth bearing portion of the top end wall had to be flexed by force applied between the outer supporting skirt and the inner dome in order to bring the teeth on the two end walls into engagement with each other. The amount of force required to deflect the teeth was considered by some users to be too great for this prior art closure.

In accordance with the present invention, the amount of axial directed force required to flex the outer cap teeth 31 into engagement with inner cap teeth 35 is substantially reduced by providing, on a central portion 40 of the top end wall 33 of the outer cap an upper dome 41 constructed in a novel manner providing resilience while still providing means at the center of the inner and outer caps to space their respective teeth until sufficient downward force is exerted. These ends are achieved by forming the upper dome 41 as a segmented ring having flexible ring segments 43 projecting into abutment with the dome 39 on the lower cap 14 and deflecting readily with depression of the center portion 40 of the upper cap. Preferably, the ring segments 43 are thin in cross section and are flared outwardly from their upper to lower ends to facilitate their being cammed outwardly by the dome 39 with depression of the center portion of the top end wall 33. In this deflected condition, the ring segments are stressed and will provide a restoring force to lift the teeth 31 when the manually exerted downward force is released.

Referring now in greater detail to the illustrated safety closure 11, the outer cap 12 is formed in one piece by molding a relatively flexible resilient plastic such as polyethylene or polypropylene. Thus, the top end wall 33 is made of a flexible material for deflecting with axially directed pressure. The end wall 33 is integrally joined at a rounded comer 48 with the depending skirt 21.

Within the interior of the outer cap 12, a series of ra- I dially extending teeth 31 are integrally molded on the top end wall 33 and project downwardly from inner side 51 of the top end wall 33. The teeth are elongated with lower bottom walls 53 disposed in a plane spaced from and parallel to the plane of the inner side 51 of the top end wall. Preferably, the teeth 31 are equally spaced from and angularly spaced about an axis through the center of this top end wall. Also, each of the downwardly projecting teeth is formed with a pair of vertical, parallel side walls 55 extending from inner rounded tooth ends 57 to outer rounded tooth ends 59. The side walls 55 define therebetween triangular wedge shaped slots for the reception of the triangularly shaped lower teeth on the lower cap 14.

More specifically and as best seen in FIG. 5, the teeth 35 on the inner cap 14 project upwardly from an upper side 60 of the top end wall 37 for the inner cap and are sized to be inserted into the slots between the teeth 31 of the outer cap 12. The triangular shaped teeth 35 have narrow inner ends 62 and vertical side walls 63 which diverge outwardly to a wider arcuate outer wall 64. The spaces between the side walls 63 of adjacent fingers 35 define substantially parallel sides of grooves or slots to receive the teeth 31 of the outer cap. Thus, both the inner and outer caps having projecting teeth and alternating slots for meshing with the slots and teeth of the other.

Turning now to segmented ring means 41 for holding the caps 12 and 14 with their teeth 31 and 35 spaced, the ring segments 43 thereof rest on the dome 39 of the lower cap 14 so that the child or other user who merely rotates the outer cap will not remove the inner cap and closure from the container. The illustrated segmented ring means is formed with three segments 43 which are separated from one another by vertically extending spaces 68 between adjacent segments. The segments are integrally attached at upper arcuately shaped ends to the inner side 51 of the end wall 33 in a circular array about the axis of the outer cap; and the ring segments flare outwardly from these upper inner ends to free, lower and outer ends 70 which are arcuately shaped and in a circular array collectively defining a concave interior surface to receive the dome 39 of the inner cap in the center thereof. The free ends 70 of the segments 43 project downwardly for a distance greater than the upper teeth 31 project downwardly, as best seen in FIG. 4, and will maintain the teeth spaced from one another until sufficient axial force is provided to cam their free ends 70 radially outwardly with a simultaneous downward deflection of the top end wall 33.

The segments 43 will readily deflect unlike the rigid upper dome used heretofore for the outer cap and result in less force required to displace the end wall 33. This is in contrast to the action in the prior art closures in which the axial pressure on the abutted domes resulted only in flexing of the end wall. That is, in the prior art closures of this general kind, the abutted domes served as a first fixed point and the corners 48 served as a second fixed point and defined therebetween a short span requiring a large force to deflect the annular section sufficiently to bring the teeth into engagement.

When twisting the outer cap 12 in the clockwise application direction, the tooth abutment walls 23 on the ratchet teeth 20 abut similar tooth abutment walls 25 on the inner ratchet teeth 19 to rotate the inner cap 14 to screw the thread 18 onto a similarly threaded portion of the container. As best seen in FIG. 2, the ratchet teeth 20 on the outer cap 12 are generally triangular in cross section and project radially inwardly from inner surface 72 of the skirt 21. The ratchet teeth 20 extend downwardly from upper ends positioned adjacent the end wall 33 to lower ends 71 which are spaced upwardly above the lower ring for the outer cap 12. Each ratchet tooth decreases in cross-sectional area in the counterclockwise direction from its tooth abutment wall 23 to a trailing edge 73 which smoothly blends with the inner surface 72 of the cap skirt 21.

When the outer cap 12 is turned in the counterclockwise direction, the trailing edges 73 of its teeth 20 are turned into engagement with the inclined surfaces 29 on the ratchet teeth 19 of the inner cap 14 and are cammed thereby to flex radially outwardly about edges of flattened, reduced cross-sectional sections 74 of the outer skirt 21. By having these reduced these reduced thickness skirt wall sections 74 at three locations on the ratchet teeth 20, the skirt wall hinges and flexes radially outwardly more readily so that the friction between the inner and outer ratchet teeth encountered during tuming is not sufficient to turn the inner cap 14 in the clockwise direction to unscrew the same from the container.

For the purpose of holding the inner and outer caps against separation, an inwardly projecting retaining ring 81 (FIGS. 2 and 4) is formed on the bottom rim of the outer cap 12 to project beneath a lower rim 82 for the skirt 15 of the inner cap. During assembly, the inner cap is forced inwardly into the outer cap 12 with the retaining ring 81 being flexed outwardly by the skirt 15 until the skirt rim is disposed above the retaining ring 81 which is then free to snap beneath the skirt rim 82 as shown in the illustration of FIG. 4.

The inner cap 12 is preferably molded from relatively hard non-yielding plastic material such as polystyrene, polypropylene, bakelite or the like. The thread 18 therein is integrally molded in .the inner side wall of the skirt and the lower portion of the skirt is provided with a thicker cross section band 85 to reinforce the lower rim of the skirt. This enlarged cross-sectional band 85 projects radially outwardly into the area between the retaining ring 81 and lower ends 71 of the ratchet teeth 20 on the outer cap 12.

Thus, it will be seen from the foregoing that the present invention provides a new and improved closure which requires less downward force to engage radially extending teeth on the outer cap with interengageable teeth on the inner cap to interlock the caps for turning together to release the closure from the container. The ring 41 of resilient segments 43 may be deflected and the central portion of the upper end wall 33 carrying the same may be deflected with a considerably less force than was needed with the prior art devices to interengage the teeth.

While a preferred embodiment has been shown and described, it will be understood that there is no intent to limit the invention by such disclosure but, rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

l. A closure for fastening to containers comprising: an outer cap having a top end wall and skirt depending from an outer edge of said top end wall, an inner cap having a top end wall and a depending skirt joined to the outer edge of said end wall, said outer cap overlying said inner cap and being coaxial therewith, container fastening means on the skirt of the inner cap for releasably fastening on a portion of a container, radially and horizontally extending teeth on the upper surface of the top end wall of the inner cap extending in a first substantially horizontal plane, radially and horizontally extending teeth on the inner surface of the top end wall of the outer cap extending in a second substantially horizontal plane, vertically extending ratchet teeth on the inner wall of said outer cap skirt, vertically extending ratchet teeth in the outer wall of said inner cap skirt, said vertically extending ratchet teeth on said respective caps abutting when-the outer cap is turned in an application direction to rotate the two caps together and to cause said container fastening means to fasten said inner cap onto said container, said ratchet teeth of said outer cap sliding over said vertically extending ratchet teeth of said inner capif the outer cap is turned in removal direction, a rigid central portion on said end wall of a first one of said caps facing the end wall of the other one of said caps, a thin walled segmented ring forming a flexible dome on the central portion of the other one of said .caps, said segmented ring being dis crete from and located inwardly of inner ends of said horizontally and radially extending teeth of the other one of said caps, said segmented ring facing and engaging said central portion on said first cap at spaced locations, said segmented ring spacing in a vertical direction said horizontally and radially extending teeth on said caps from each other, said ring segments flexing with sufficient downward axial force on said outer cap to allow said center portion of said top end wall of said outer cap to lower and with further downward force to shift the horizontally and radially extending teeth on the outer cap axially, toward and into engagement with the teeth on the inner cap at locations radially outward of said central portion so that a simultaneously applied torque on the outer cap in the removal direction will act through said radially and horizontally extending teeth to turn said inner cap to release the same from the container, said ring segments being resilient and urging said center portion of said top end wall of said outer cap upwardly to assist in lifting its radially and horizontally extending teeth from engagement with the radially and horizontally extending teeth on said inner cap whereby removal of the closure can be accomplished only with a downward axial force interengaging said teeth and a simultaneously applied torque in the removal direction.

2. A closure for fastening to containers comprising: an outer cap having a top end wall and skirt depending from an outer edge of said top end wall, an inner cap having a top end wall and a depending skirt joined to the outer edge of said end wall, said outer cap overlying said inner cap and being coaxial therewith, container fastening means on the skirt of the inner cap for releasably fastening onto a portion of a container, radially and horizontally extending teeth on the upper surface of the top end wall of the inner cap extending in a first substantially horizontal plane, radially and horizontally extending teeth on the inner surface of the top end wall of the outer cap extending in a second substantially horizontal plane, vertically extending ratchet teeth on the inner wall of said outer cap skirt, vertically extending ratchet teeth in the outer wall of said inner cap skirt, said vertically extending ratchet teeth on said respective caps abutting when the outer cap is turned in an application direction to rotate the two caps together and to cause said container fastening means to fasten said inner cap onto said container, said ratchet teeth of said outer cap sliding over said vertically extending ratchet teeth of said inner cap if the outer cap is turned in removal direction, said top end wall of said inner cap having a rigid central portion, a thin-walled segmented ring having a plurality of ring segments extending downwardly from a central portion of the inner side of said top end wall for said outer cap and engaging said central portion of said inner cap at spaced locations, said segmented ring being discrete from and spaced inwardly of inner ends of said horizontally extending teeth and holding said radially and horizontally extending teeth on said outer cap at a position spaced above said radially and horizontally extending teeth on said inner cap, said ring segments being located at said center portion of said outer cap, said ring segments flexing outwardly within response to exertion of a downward axial force onsaid outer cap and said central portion of said top end wall deflecting downwardly to shift the radially extending teeth on the outer cap located radially outwardly of said center portion axially toward and into engagement with the teeth on the inner cap so that a simultaneously applied torque on the outer cap in the removal direction will turn said inner cap to release the same from the container, said ring segments being resilient and urging said deflected center portion of said top end wall upwardly to assist in lifting its teeth from engagement with the teeth on said inner cap whereby re moval of the closure can be accomplished only with a downward axial force interengaging said teeth and a simultaneously applied torque in the removal direction.

3. A closure in accordance with claim 2 in which said ring segments flare outwardly and downwardly to free ends and define a concave surface, said central portion of said inner cap defining an upwardly projecting dome in alignment with said concave surface.

4. A closure in accordance with claim 1 in which the center portion of said top end wall of said top cap is planar and substantially horizontally disposed above said segmented ring.

5. A closure for fastening to containers comprising: an outer cap having a top end wall and skirt depending from an outer edge of said top end wall, an inner cap having a top end wall and a depending skirt joined to the outer edge of said end wall, said outer cap overlying said inner cap and being coaxial therewith, container fastening means on the skirt of the inner cap for releasably fastening on a portion of a container, interengageable and radially and horizontally extending teeth on the upper surface of the top end wall of the inner cap extending in a first substantially horizontal plane, radially and horizontally extending teeth on the inner surface of the top end wall of the outer cap extending in a second substantially horizontal plane, vertically extending ratchet teeth on the inner wall of said outer cap skirt, vertically extending ratchet teeth in the outer wall of said inner cap skirt, said vertically extending ratchet teeth on said respective caps abutting when the outer cap is turned in an application direction to rotate the two caps together and to cause said container fastening means to fasten said inner cap onto said container, said ratchet teeth of said outer cap sliding over said vertically extending ratchet teeth of said inner cap if the outer cap is turned in removal direction, a rigid central portion on said end wall of a first one of said caps facing the end wall of the other one of said caps, a thinwalled ring means forming a dome on said central portion of the other one of said caps, said ring means being discrete from and located inwardly of inner ends of said horizontally and radially extending teeth of the other one of said caps, said ring means facing and engaging said central portion of said first cap at spaced locations, said ring means spacing in a vertical direction said horizontally and radially extending teeth on said caps from each other, a downward force on said outer cap engaging said radially and horizontally extending teeth on said inner and outer caps so that a simultaneously applied torque on the outer cap in the removal direction will act through said radially and horizontally extending teeth to turn said inner cap to release the same from the container, said skirt of said outer cap having reduced cross sectional thickness portions adjacent the ratchet teeth on the cap for hinging and flexing outwardly to reduce the friction and torque being applied between said vertically extending ratchet teeth on said outer cap and said vertically extending ratchet teeth on said inner cap so that said outer cap will ratchet past said inner cap while said inner cap remains stationary. 

1. A closure for fastening to containers comprising: an outer cap having a top end wall and skirt depending from an outer edge of said top end wall, an inner cap having a top end wall and a depending skirt joined to the outer edge of said end wall, said outer cap overlying said inner cap and being coaxial therewith, container fastening means on the skirt of the inner cap for releasably fastening on a portion of a container, radially and horizontally extending teeth on the upper surface of the top end wall of the inner cap extending in a first substantially horizontal plane, radially and horizontally extending teeth on the inner surface of the top end wall of the outer cap extending in a second substantially horizontal plane, vertically extending ratchet teeth on the inner wall of said outer cap skirt, vertically extending ratchet teeth in the outer wall of said inner cap skirt, said vertically extending ratchet teeth on said respective caps abutting when the outer cap is turned in an application direction to rotate the two caps together and to cause said container fastening means to fasten said inner cap onto said container, said ratchet teeth of said outer cap sliding over said vertically extending ratchet teeth of said inner cap if the outer cap is turned in removal direction, a rigid central portion on said end wall of a first one of said caps facing the end wall of the other one of said caps, a thin walled segmented ring forming a flexible dome on the central portion of the other one of said caps, said segmented ring being discrete from and located inwardly of inner ends of said horizontally and radially extending teeth of the other one of said caps, said segmented ring facing and engaging said central portion on said first cap at spaced locations, said segmented ring spacing in a vertical direction said horizontally and radially extending teeth on said caps from each other, said ring segments flexing with sufficient downward axial force on said outer cap to allow said center portion of said top end wall of said outer cap to lower and with further downward force to shift the horizontally and radially extending teeth on the outer cap axially toward and into engagement with the teeth on the inner cap at locations radially outward of said central portion so that a simultaneously applied torque on the outer cap in the removal direction will act through said radially and horizontally extending teeth to turn said inner cap to release the same from the container, said ring segments being resilient and urging said center portion of said top end wall of said outer cap upwardly to assist in lifting its radially and horizontally extending teeth from engagement with the radially and horizontally extending teeth on said inner cap whereby removal of the closure can be accomplished only with a downward axial force interengaging said teeth and a simultaneously applied torque in the removal direction.
 2. A closure for fastening to containers comprising: an outer cap having a top end wall and skirt depending from an outer edge of said top end wall, an inner cap having a top end wall and a depending skirt joined to the outer edGe of said end wall, said outer cap overlying said inner cap and being coaxial therewith, container fastening means on the skirt of the inner cap for releasably fastening onto a portion of a container, radially and horizontally extending teeth on the upper surface of the top end wall of the inner cap extending in a first substantially horizontal plane, radially and horizontally extending teeth on the inner surface of the top end wall of the outer cap extending in a second substantially horizontal plane, vertically extending ratchet teeth on the inner wall of said outer cap skirt, vertically extending ratchet teeth in the outer wall of said inner cap skirt, said vertically extending ratchet teeth on said respective caps abutting when the outer cap is turned in an application direction to rotate the two caps together and to cause said container fastening means to fasten said inner cap onto said container, said ratchet teeth of said outer cap sliding over said vertically extending ratchet teeth of said inner cap if the outer cap is turned in removal direction, said top end wall of said inner cap having a rigid central portion, a thin-walled segmented ring having a plurality of ring segments extending downwardly from a central portion of the inner side of said top end wall for said outer cap and engaging said central portion of said inner cap at spaced locations, said segmented ring being discrete from and spaced inwardly of inner ends of said horizontally extending teeth and holding said radially and horizontally extending teeth on said outer cap at a position spaced above said radially and horizontally extending teeth on said inner cap, said ring segments being located at said center portion of said outer cap, said ring segments flexing outwardly within response to exertion of a downward axial force on said outer cap and said central portion of said top end wall deflecting downwardly to shift the radially extending teeth on the outer cap located radially outwardly of said center portion axially toward and into engagement with the teeth on the inner cap so that a simultaneously applied torque on the outer cap in the removal direction will turn said inner cap to release the same from the container, said ring segments being resilient and urging said deflected center portion of said top end wall upwardly to assist in lifting its teeth from engagement with the teeth on said inner cap whereby removal of the closure can be accomplished only with a downward axial force interengaging said teeth and a simultaneously applied torque in the removal direction.
 3. A closure in accordance with claim 2 in which said ring segments flare outwardly and downwardly to free ends and define a concave surface, said central portion of said inner cap defining an upwardly projecting dome in alignment with said concave surface.
 4. A closure in accordance with claim 1 in which the center portion of said top end wall of said top cap is planar and substantially horizontally disposed above said segmented ring.
 5. A closure for fastening to containers comprising: an outer cap having a top end wall and skirt depending from an outer edge of said top end wall, an inner cap having a top end wall and a depending skirt joined to the outer edge of said end wall, said outer cap overlying said inner cap and being coaxial therewith, container fastening means on the skirt of the inner cap for releasably fastening on a portion of a container, interengageable and radially and horizontally extending teeth on the upper surface of the top end wall of the inner cap extending in a first substantially horizontal plane, radially and horizontally extending teeth on the inner surface of the top end wall of the outer cap extending in a second substantially horizontal plane, vertically extending ratchet teeth on the inner wall of said outer cap skirt, vertically extending ratchet teeth in the outer wall of said inner cap skirt, said vertically extending ratchet teeth on said respective caps abutting when the outer cap is turNed in an application direction to rotate the two caps together and to cause said container fastening means to fasten said inner cap onto said container, said ratchet teeth of said outer cap sliding over said vertically extending ratchet teeth of said inner cap if the outer cap is turned in removal direction, a rigid central portion on said end wall of a first one of said caps facing the end wall of the other one of said caps, a thin-walled ring means forming a dome on said central portion of the other one of said caps, said ring means being discrete from and located inwardly of inner ends of said horizontally and radially extending teeth of the other one of said caps, said ring means facing and engaging said central portion of said first cap at spaced locations, said ring means spacing in a vertical direction said horizontally and radially extending teeth on said caps from each other, a downward force on said outer cap engaging said radially and horizontally extending teeth on said inner and outer caps so that a simultaneously applied torque on the outer cap in the removal direction will act through said radially and horizontally extending teeth to turn said inner cap to release the same from the container, said skirt of said outer cap having reduced cross sectional thickness portions adjacent the ratchet teeth on the cap for hinging and flexing outwardly to reduce the friction and torque being applied between said vertically extending ratchet teeth on said outer cap and said vertically extending ratchet teeth on said inner cap so that said outer cap will ratchet past said inner cap while said inner cap remains stationary. 